The doctrine of atomism,
a Greek innovation introduced by philosophers Leucippus of Miletus and
Democritus of Abdera in the 5th century BC, describes a universe in which
all tangible things are composed of minute indivisible particles of
matter: atoms.Epicurus subsequently developed a modified theory atomism for his
own philosophical system, using it as a basis to tie in his
epistemological and ethical theories.

Atoms Defined

In
our age, the word atom is most typically used to denote a periodical element—a system of protons, neutrons, and electrons,
which conjures up the image of a miniature solar system. These are
not atoms in the classical sense.It
was merely by linguistic accident that the elements listed on periodic
tables became known as atoms—not unlike how the native Americans became
known as Indians.For just as
Christopher Columbus crossed the Atlantic and thought he had arrived at
India, chemists in the 19th century isolated such substances as Hydrogen,
Carbon, and Oxygen, and thought they had arrived at the ultimate building
blocks of all existing things—but in fact, they still had a ways to go,
as was confirmed when physicists later “split the atom” in the very
next century.

The atoms
of the ancient philosophers are what modern particle physicists now call
fundamental particles. Even today, we do not know for sure which of the known
particles are indeed fundamental, nor how many different types of them
may ultimately exist.The electron
could very well be a fundamental particle—to date, no one has ever
“split the electron.”Protons
and neutrons, by contrast, are
definitely not fundamental particles—these larger entities turn out to
be formed by trios of sub-particles called quarks.
And what are quarks made of? The mystery continues to
unfold.

However, contemporary physicists
nearly all agree that particles of matter cannot be broken down for ever
and ever—there must be some quantum level at which particles are
irreducible. We can be assured of this because it is apparent that
the way that matter behaves at the scale of electrons and quarks, is
wholly different from the behavior we see on the scale of billiard balls
or planets.This is because particles exhibit quantumeffects—their
measured qualities are limited to discrete
values. If particles were infinitely divisible, then any
object could be scaled down to any size without being subject to such
effects: there would be no reason for matter to group itself together
into periodic elements, and, just as in the tales of Gulliver’s
Travels, everything we know of could exist in any size: people,
cities, worlds, or what-have-you.But
indeed this is not the case.Scale matters, because
the building blocks of all things are discrete entities of fixed sizes.

Permanence of Matter

The atoms of Democritus and Epicurus
were also deemed to be eternal,
i.e., they can neither be destroyed, nor created.This universal law is what contemporary physicists deem the “law
of conservation”—and it applies equally to mass and energy.

People are born young and grow old, but
in one aspect, we are all the same age: all of the matter in our bodies is
as old as the universe.Before
they became a part of us, each one of our “personal” atoms had been
somewhere else: in the air we eventually breathed, the water we eventually
drank, and the food we eventually ate.And before then, they resided in the soil of the earth, the
scattered dust of outer space, and even in the blazing depths of ancient
stars.When we die, our
bodies will be dissolved into their elements, which shall continue on
without us to be redistributed throughout the world.The planet Earth itself will eventually break down at some
unknown time many eons from now, and all of its
elements will be carried away by the exploding sun and strewn throughout
space.From those ashes,
new worlds may be formed as the atoms regroup.But the creation of anything new may only come about by the
demolition of something previously existing: you can’t get something
from nothing.

If matter cannot be created, how do we
then account for the creation of the universe?It must stand to reason that all matter that exists today has
existed for all time.Does
that mean forever—an infinite amount of time?That is indeed what the ancient Epicureans naturally assumed, but it
may not be necessarily so.

Properties of Space

Matter is not the only thing that exists
in the universe.There is
also a counterpart to matter, which the ancient atomists called the void.The term is used
to describe the emptiness of unoccupied places, a concept that we usually
regard as space.Just because the void is essentially “nothingness,” it
still does exist, as an
intangible medium that contains and conducts the transportation of matter.If only matter existed without the accompaniment of void, the
atomists reasoned, then nothing could ever move, because the entire
universe would be packed absolutely tight with matter.But the void is a perfect superconductor, utterly passive,
presenting no friction whatsoever to the atoms which pass through it.

Matter and void are the fundamental
constituents of all existence, and the Epicureans asserted that no third constituent is possible.If something is tangible to any degree, then it contains
material—what dif not, then it is merely spatial.All the phenomena that we know of, or that we attempt to discover,
or that we care to speculate about, can and must be accounted for in terms
of indivisible bodies moving through empty space.

Besides intangibility, another essential
property of the void is its boundlessness,
meaning that it is not delineated by any boundaries, edges, or
extremities.Does this mean
that the reaches of space extend forever and that the universe is
infinitely large? The
Epicureans thought so, for if there was indeed an “end of the
universe,” what would happen, as Lucretius supposed, if someone went
there and threw a spear beyond the point where he was?One of two things would happen: either the spear would proceed
onwards, or something would get in its way.In either case there would have to be something
beyond that point.In neither
case has one arrived at the end of the universe.This type of persuasive reasoning carried on for ages, and was
believed by most every scientific thinker, including the young Albert
Einstein.

Modern Cosmological Considerations

However, once Einstein had developed the
principles of general relativity
in 1915, the way had been paved for a new possibility: a boundless
yet finite universe.What
makes this arrangement possible is that the “void” has yet another
attribute, unimagined by the ancients, which is: shape.Gravity, according to General Relativity, is an effect of curved
space.If space can be
curved, then the dimensions of the universe could very well be circular,
not unlike the dimensions of the Earth.The analogy is an apt one, because it’s easy for anyone today to
realize that the Earth’s surface has no “ends,” but is a continuous
plane wrapped upon itself—and in spite of having no such boundaries, the
Earth’s surface is definitely not
infinite.We can imagine what
would happen if Lucretius departed from Rome to throw his spear off the
“edge of the Earth”—in his quest to find it, he would march and sail
along a straight path, unwittingly circumnavigating the entire planet, and
winding up right back where he started from.This would happen no matter what direction he traveled: east,
north, southwest, etc. He
might be driven to conclude that “all roads lead to Rome” indeed!

Although it is much more difficult to
visualize, the same principle can be applied to three-dimensional
space curved upon itself.This
implies that a hypothetical expedition across the universe in any
particular direction would always lead the imaginary space traveler back
to where he started—regardless of his direction of travel.
However, we should not expect such a bold voyage to succeed, because it is
now believed that the universe is expanding faster than any
spaceship could ever travel.

This most revolutionary discovery came
in 1929, at the Mt. Wilson Observatory in California, where astronomer
Edwin Hubble measured and cataloged the distances of galaxies.As he compiled his data, he found a general correlation between
distance and space motion: the further away a galaxy was, the faster it receded from Earth
(and consequently: from all the other galaxies too).The immediate implication of this observation was that the universe
was spreading itself thin.So if matter
disperses itself over time, an even more profound implication follows: the
further back you trace the history of the universe, the denser the
universe must have been.Trace
back far enough, somewhere between 12 and 20 billion years ago, and
you’ll have reached a point of infinite
density.The entire universe
was then contained within the space of a pinprick.From this infinitesimal spot came pouring forth all the matter that
exists, in a violent expulsion that echoes down to the present day.The big bang theory was
born.

Relativity, curved space, and the Big
Bang may seem far removed from the humble cosmology of an ancient Greek
like Epicurus, but this modern framework will provide us with a novel
means of substantiating one of Epicurus’ most controversial conjectures:
the atomic swerve.

The Atomic Swerve

In the atomic system of Democritus,
cosmology is entirely deterministic,
meaning that everything that happens in the universe is the inevitable
consequence of what happened before.According to this view, the trajectory of each and every atom
proceeding along straight-line paths that are solely altered by inevitable
collisions with other atoms throughout the course of history—all events,
past, present, and future, including the fact that you exist and are
reading this sentence right now, are dictated by fate.Epicurus, contrarily, proposed that as atoms traverse the void,
they may deviate from a straight-line path at “uncertain times and
places.”These random
deviations are very slight, and they occur without any connection to the
behavior of other atoms.In
philosophical terms, Epicurus takes on the position of indeterminism,
meaning that whatever happens in the universe is incidental, rather than inevitable.

Contemporary physicists still disagree
as to whether matter behaves in a fundamentally deterministic or
indeterministic manner.The
1927 discovery of the uncertainty
principle, by Werner Heisenberg, has been a prominent catalyst for
this debate.The dilemma
which the principle presents, is that it is impossible to ascertain both
theposition and momentum of any
particle with precision—the more accurate determination of the one must
entail a less precise measurement of the other.Because of this inherent imprecision, a degree of
“indeterminism” must be factored into predictions, within certain
limits of probability.However,
when we speak of “indeterminism” in its full philosophical sense, we
are talking about a stronger meaning: random deviations that are axiomatic—a fundamental property of matter itself.Now because there are limits to what can be measured, as Heisenberg
discovered, all this implies is that we can’t make assertions about
the events operating beyond those limits.So the uncertainly principle does not substantiate either side of
the argument.

Epicurus’ criticism of Democritus’
determinism, however, stems from a much more blatant observation—an
observation as large as the universe itself: if elements never deviated from
straight-line paths through the void, how would they have ever found an
occasion to collide in the first place?Why
wouldn’t the atoms just rain down in parallel paths forever?This is exactly the same issue that cosmologists are struggling
with today in attempting to describe the early history of the universe.They want to know how it came about that nature abounds with
groupings of galaxies, stars, and planets, rather than an evenly distributed atomic
fog.

In
1992, an exciting experiment was undertaken to investigate how the
universe evolved the structure it has today: the COBE satellite project.The microwave detectors onboard this craft mapped the cosmic
background radiation which appears at the “edge” of the visible
universe in every direction we look.What we are actually seeing there is the light given off by the
receding plasma which constituted the dense early universe (now arriving
as microwave energy due to wavelength elongation caused by the Doppler
effect). The resulting map depicted minute temperature variances
distributed chaotically—regions of higher temperatures signifying areas
of higher density.The areas
of higher density would later form the complex structures of galactic
clusters that we see today, while the pockets of lower density would
become rapidly dispersed in intergalactic space.

The great scientific/philosophic
question surrounding these findings is: what would account for these
variances?If,
at the initial state of the universe, all matter was packed into a
geometric point, then the initial condition of the universe started was a
symmetrical, homogenous arrangement—it makes no
sense, after all, to speak of a “lop-sided” zero-dimensional point!But if the evenly spaced atoms of the early universe were to have
fanned out in parallel rays, powdering space with equal atomic density,
the variances in temperature that we see in the COBE images could not
exist—and neither would the galaxies, worlds, nor us!

Hence, the Epicurean theory of the
“atomic swerve” provides an accounting for that
“initial lateral motion”
which made subsequent atomic collisions possible.It is therefore reasonable to assume that atoms are still
“swerving” today.